When the temperature is below 600℃, the specific surface area of carbonized material increases with the increase of temperature.When 600~900℃, the specific surface area reaches a certain value: 250~300 m2/g; when above1000℃, the specific surface area shrinks rapidly.
When the carbonization temperature is above 800℃, the reaction performance of carbonized compounds and activation gas gradually becomes weaker, so the carbonization temperature is generally below 1000℃. However, if the residual volatile content and thermal effect are taken into account, the most suitable temperature should be 600~700℃39].gold recovery activated carbon
The carbonized substance obtained from the carbonization process is placed in water vapor or a mixture of water vapor and combustion gas and heat treated at 800~1000℃, which is called the activation process.coconut activated carbon factory
The commonly used activation gases are carbon dioxide, water vapor, oxygen, etc., due to the oxidation reaction of these gases on the surface of the carbonized substance, eroding the carbonized substance, thus producing a rich porous structure.(2) Chemical method.
Chemical activation method is a method of preparing activated carbon by adding chemicals to the raw materials used or impregnation into the raw materials or carbonized materials, and then heating it at high temperature in inert gas.The chemicals used in chemical activation are generally dehydrating.The more commonly used activator is: inorganic acid varieties have phosphoric acid, sulfuric acid and boric acid, salt varieties have zinc chloride, calcium carbonate and potassium sulfate, alkali varieties have sodium hydroxide, potassium hydroxide, etc.